1. Field of the Invention
The present invention relates to a communication terminal device with both-side receiving function.
2. Description of the Related Art
A communication terminal device capable of carrying out communication by a communication procedure with both-side recording specified has been developed recently. In such a communication terminal device, images which are received by both-side receiving are recorded on both sides of recording paper. For communication modes during both-side communication, there are a continuous mode and an alternate mode. The continuous mode is a mode to continuously carry out transmission of the images that are to be front pages, and to transmit the images that are to be back pages after the completion of the transmission of the images of the front pages. For example, this continuous mode is suitable for the case in which an image reading apparatus of a transmitting side has a mechanism for reading the other of the sides continuously after continuously reading one of the sides of the documents, or for the case in which the recording apparatus of the receiving side has a mechanism for continuously recording images of the front pages on one sides of the paper, and then carrying out the continuous recording of the back pages after stacking and placing the paper again with the paper reversed. On the other hand, the alternate mode is a mode for transmitting the image of the front page and the image of the back page alternately. For example, this alternate mode is suitable for the case in which the image reading apparatus of the transmitting side has a mechanism to read the other side by reversing a document right after reading one side of the document, or in the case in which the recording apparatus of the receiving side has a mechanism for recording an image of a back page on the other side of a sheet of paper by reversing the paper immediately after recording an image of a front page on one side of the sheet. In either mode, the page number can be attached and transmitted in the post command after the transmission of the image of one page.
According to the continuous mode mentioned above, in the receiving side, this mode is preferable for the case in which the recording apparatus has a mechanism to continuously perform recording of one side of the paper, to stack the paper and then to carry out the recording of the back pages by reversing the paper. However, for the recording apparatus which carries out reverse recording of the sheets of paper one by one, the recording cannot be started each time the image of the front page is received. Therefore, it is necessary to store the images of the front pages which are transmitted continuously in the image memory, and to start the recording when the images of the front page and the back page is complete after receiving the back page image. In this case, there are cases in which the page of the back page image starts from the head side, and the page of the back page image starts from the end side. Therefore, there are a case in which the recording cannot be started at the point of time when starting the receiving of the back page image. As a result, conventionally, the recording and outputting is started after the completion of the reception of the images of all pages.
However, in order to keep storing the images in the image memory until the receiving of the images of all pages is completed, an enormous amount of memory is required. Therefore, for example, there were problems in that the storing of the image to be transmitted was obstructed due to the image memory being occupied excessively by the received images.